Surface maintenance equipment is available in a wide variety of types and sizes. Certain of such equipment is designed for indoor use while other equipment is particularly adapted for use in caring for large outdoor areas such as parks, parking lots and the like. The present invention is generally of the latter type, although it may be used in any desired area.
Surface maintenance equipment typically has included a body portion supported on a plurality of wheels. The equipment will include a power source such as a gasoline engine or an electric motor. The power source drives certain of the wheels as well as driving vacuum equipment. The body usually will carry a hopper for containment of dirt and debris which has been picked up. In some instances the equipment will be an articulated structure including a cab portion and a trailer portion. The equipment generally has a debris pickup housing which defines a zone from which the dirt and debris is lifted and deposited in the hopper. A rotatably driven cylindrical tool, typically a brush or a paddle structure, may be disposed in the pickup housing to assist in lifting the dirt and debris. A duct may provide communication between the debris pickup housing and the hopper. Such surface maintenance equipment of course also includes various controls such as steering mechanisms, speed controls and the like. The general type of equipment contemplated in the present invention is illustrated in U.S. Pat. Nos. 3,837,038 (Kimzey) and 3,881,215 (Krier et al.), which are assigned to Tennant Company. This type of equipment will generally include a flexible skirt structure around the lower periphery of the debris pickup housing. The flexible skirt structure assists in providing a partial seal between such housing and the surface being swept. The skirt further aids in dust control and minimizes undesirable projection of debris. The skirt also permits upward spacing of metal parts of the housing to prevent damage from undulations in the surfaces, large pieces of debris, and the like.
It is important for efficient operation of sweeping equipment that the skirt structure maintain the partial seal. Problems have been encountered in some instances wherein the skirt structure is pulled up out of engagement with the surface and, for example, becomes caught by the rotating cylindrical tool and lifted to a position where the skirt is inoperative. This problem is particularly apparent in those instances where the cylindrical tool rotates with sweeping being in a forward direction.